1 (interjection).A war cry chanted when someone (male or female) stumbles, trips, or otherwise falls over in public, to the amusement of others and the embarrassment of themselves. The chant is often accompanied with an elbow-drop being inflicted on the fallen victim.
2 (noun) An instance of the above occurrance.

"We were walking down the street when a man tripped up, so we rushed over and gave him a She Fell Over."